Improvement in construction of round and half-round files



NITED STATES ATENT OFFICE.

IMPROVEMENT IN CONSTRUCTION 0F ROUND AND HALF-ROUND FILES.

Specitieation forming part of Letters Patent No. 43,775, dated August 9,1864.

.To all 1071/0711/ it may concern,.-

Be it known that l, J. NELsoN JACOBS, of NVorcester, in the count-y ot'Worcester and State of Massachusetts, have invented a new and usefulImprovement in the Construction of Round and Half-Round Files; and I dohereby declare that the following is a full, clear, and exactdescription thereof, which will enable others skilled in the art to makeand use the same, reference being had to the accompanying drawings,making a part of this specih'cation, in which- Figure l represents aside view of a halfround tile constructed according-to my invention;Fig. 2, atransverse section ot' the same taken in the line 06,*Fig. l;Fig. 3, an end View of a iat steel plate, which is rst cut and then bentin round or half-round form.

The ordinary round and half-round les are constructed by rst rolling orswaging the steel in the desired form, technically termed blanks andthese blanks are then cut in order to form the tile. The fiat tiles maybe constructed in this way in a perfect manner,

but round and half-round [iles cannot be perfectly cut, as thecutting-tool destroys the rotundity ot the surface, which, instead ofbeing` round or half-round, is of polygonal form.

By my improvement I can construct a round or halt' round tile with aperfect curved surface either circular or semicircular in its transversesection. To ett'ect this I construct blanks out or" sheet-steel platesof any desired dimensions, according t-o the size of the tile required,and out said blanks, either manually or by a machine, in the same way asthe ordinary tlat or tri-lateral tiles are cut. These plates are thenheated and bent, or bent without heating, so as to form a circle orsemicircle in their transverse section, and are then tempered. The tilesthus constructed may remain in shell form, or, in cases Where weight andsolidity are required, they may be filled with wood or soft metal; atangto receivea handle being attached to one end of them. By thisarrangement I obtain a tile of the kind specified, with aperfect curvedsurface,

and consequently one which willoperate much more perfectly than thoseconstructed in the ordinary Way. Besides, I eiiect a saving in metal, aswell as in. the cost of manufacture. Brass and copper tiles, which aresometimes used for particular kinds of work, do not require to have theiat plates heated in order to be bent. They are bent while in a coldstate.

Fig. l shows a haltl round tile, A, in a tinished state, Fig. 2, atransverse section of the same; Fig. 3, an end view of a Hat plate, a,cut and ready to be bentin the form shown in Figs. l and 2.

I claim as new and desire to secure by Letters Patent- The processherein described ot' constructing` round and half-round tiles-t0 wit, byforming the blanks of flat metal plates, cutting the same, and thenbending them in the round or half-round form.

J. NELSON JACOBS.

Witnesses J AMES H. BANoRoFr, W. C. WILLiAMs.

